The Waterford Steam Electric Station, Unit 3, also known as Waterford 3, is a nuclear power plant located on a 3,000-acre (12-km²) plot in Killona, Louisiana, in St. Charles Parish.

This plant has one Combustion Engineering two-loop pressurized water reactor. The plant produces 1,218 megawatts of electricity since the site's last refuel in October 2009. It has a dry ambient pressure containment building.

On August 28, 2005, Waterford shut down due to Hurricane Katrina approaching and declared an unusual event. Shortly after Katrina, Waterford restarted and now is in normal operation.

Entergy is planning to replace the unit's two steam generators as well as the reactor vessel closure head and control element drive mechanisms during a refueling outage in 2011. The project is estimated to cost $511 million. The steam generators are being replaced due to normal wear and tear on the equipment. Waterford 3 is one of the last units in its class to replace its steam generators. Entergy petitioned the Louisiana Public Service Commission on June 27, 2008, for approval of the project.

Ownership

Waterford is operated by Entergy Nuclear and is owned by Entergy Louisiana, Inc.

Surrounding population

The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.

The 2010 U.S. population within 10 miles (16 km) of Waterford was 75,538, an increase of 7.4 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80 km) was 1,969,431, a decrease of 0.8 percent since 2000. Cities within 50 miles include New Orleans (33 miles to city center).

Seismic risk

The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Waterford was 1 in 50,000, according to an NRC study published in August 2010.